Artificial noise scheme to ensure secure communications in CWSN

This paper presents an artificial noise strategy to increase physical-layer security in Cognitive Wireless Sensor Networks (CWSN). Spectrum sensing, information sharing and collaborative cognitive features are used to avoid eavesdropping attacks. Artificial noise generation is proposed to conceal the secret message to be transmitted. One important design parameter, the ratio of power allocated to the information bearing signal versus the artificial noise Φ is defined. A simulation framework has been used to simulate different scenarios. The simulations results show that there is a near-optimal Φ value, from 0.8 until 0.96 depending on the number of collaborator nodes, increasing with the number of relay nodes in the network. Also, the simulations show that the more nodes used for the collaboration strategy the less noise per signal is needed for the same Secrecy Outage Probability. As a result, the artificial noise strategy is seen to be highly effective for increasing the secrecy in CWSN.